Means for supplying moisture to hygrometers, humidity regulators, and the like



June 1930. A. J. LOEPSINGER ,7 MEANS FOR SUPPLYING MOISTURE TO HYGROMETERS,

' HUMIDITY REGULATORS, AND THE LIKE Filed Jan. 50, 1924 ATTORNEYS Jul-16,1930.

A BE T J, Lonrslirenn on rrlov'rnnncn, nr-roinn isrisun nsslenon;'BY iunsnn Aslsiemvrnnms, To GENERAL rrnnnxrmeursnnn- COMPANY, OF :enovInENcn, BHODE 4; ,5 I'-ISLA1\TD,,A-CORPOBATIQITQF nELnWen-n. a v e min FOR surrnrme moisten-mo nyenorvrnrnns, rrUIvrrnrrY nEGULAToi-xs, Ann

- 1 THE'LIKE"Y v I Y'Tliis invention relates means, for supplying moisture to rhygromet'ers, humidity regulators, and the like, for thev wet mpe a u e c T 1 (such instruments we equal thermally responsive element's, known as the wet dry bulb elements, are exposed {the latter to temperature of the surrounding atmosa phere, and the torment-o1 temperature which a is lower, in a degreefdepending upon the dryness of the air, jascertainedi'by the rate atgrwhich moisture'evaporates into it with A textilemateriahbut this collects dirt which sooner or'later clogs thefabri'c, so "that.

consequent depression of temperature; This wetf bulb element is, in one type of instru 'ment," supplied with 'inois ture' ii'or evaporae 'tionby meansof a wick'rising from sup- I ply of waterand surrounding it. The wicks now in common useare preferably made 0]":

water is not as readilyt'aken up, or evaporated. 1 Tllhen follows an inaccurate operation of thewet bulb element, which is'cured' only by :occasional' cleaning or" renewal*'of the wick. The elimination or wick troubles and consequent inaccuracies are objects of the present'inventlon.

Among its features s the provision of a wick, which, may also be a Jacket for the wet jbulb or wetb'ulbfelement, having; the characteristic that in ordinary operation its surface does not become sensibly wet.. Another feature is to have a wick whose surface exposedt'o air when in opera-v tion haslittleor no tendency to collect for-" eign matter.

ranged for immersion.- '1 Such a wick can be made in one p1ece,orf1n two or more parts, in, which lattfe'r' 'casejeach part by 'itself: should'have access to the water supply,

} quality of cera ic material is contrived unselected "welsh is SOPQrOusJa-s to take up water 'readily by capillary action, andj yet 1s so finely porous that at ordinary operating humidities the water which it raises is; I

evaporatedas rapidly as it is raised, where'- by the wick: surface which is accessible to touch, or to foreign bodies "floating bylin of evaporative power over capillary power, which is not attainable .in ordinary cotton wicking, nor is necessarily ;.found in a ceramic wick, isattained by imposingsufficient restraint on the capillary power, The I c efiect'is enhanced by having a surface which is free {from filamentary projectionsi ltjis not inconsistent with this, described dryness that a icha'nge of color 7 may be seeni the surface 9 6 1 3 'p n immersion" of the base of thewick; nor does this; necessarily,

mean "thattheisurfa'ce of the wick'jwould: i

ample, a piece ofcloth, ,It has" been found not wet an article laid .upon it, as for ex-,

possible to get the benefits of 'theinventi'on' v under circumstances in which 'sufiicient mois? ture' ispresen tpfor each of those phenomena to occur,fand yet there 1s no water visi- 1 the air, always feels dry. l This superiority ble'in' thehform of beads, or film, norfdis- 'coverablefby the" touch of ones finger, which condition is herein referred .to as absence of sensible moisture or dryness. .Asa' conse quence the facilities for evaporationi remain substantially uniform during, the operative,

life of fthe wick, and the 'ternpe1"at'uredread; 'ings of the-wet bulbf'lthermometer continue;

correspondingly, accurate;

A particular ceramic material-which has;

and known inthe trade' as alunduinor ,refractofryfalumlna. Experiments with one of? the coarsest commercial grades ofthis, as

been found suitable is crystalline; alumina v of thegtype produced by electric furnace];

made forufilteringdevices, known comin'erv cially asj. ;li aving porosity R A 98?, have given satisfactory results. For the pur ses unglazed'and have a surface not likely to col lect lint, fuzz or dirt.' Owing its orosit y} this'ffiltering material has capillary power to raisewater; andowingto" ts earthy na insoluble, rigid, yfiinay be of the inuenti'ontheicerainic wick should be modified form of 'sujchvvick. L

Figure -3'Jis a perspective showing i V I v p p h I 7' Y atmospherictemperature,and thus causing,

' fly i s nd' thick tolbesatiisfactorily I jifracture. I I i The invention is shown herein as applied exist in the invention disclosed.

Inthe accompanying drawings"? ,Figure 1 is an elevation of a humidit 'contr'ollerf embodying wicks having the characteristics of the present invention;

' ",Fig'ure 2-isa perspective of :one voii the K I i I WlClC decreases, causing less depression of ceramie' 'wicks; shown in Figure 1; and

The;drawings illustrate almniidity con; troller embodying principles which are more particularly disclosed in United States Patent No;l,l8l,25l,kgranted January 22,.

1924. In this "the operation of humidifying V apparatus '(notisho'wn) is controlled by air pressure "conveyed by suitable connections 1 through a lever v lve lOvvhose opening and closing are ,effeot'edby alever 12 connected vvithJjtlie'diaphragm of a .relay valve 14.

movements of ithisldiaphragin are de pendent upon the pres'sure exerted upon fit by 1i air. admitted-[and released therefromthrough'a ratio valve '16} This valve 'in'turn isfaetuate'd by l' the relative. or co -operativeefl'ect ofthe e ansio s and contractions of a-dry bulb element'. 18 fanda' l tvet bulb ele-- ment20, the former beingres'ponsive only- .to temperature' changes in the atmosphere; a andthe, latter being influenced also the humidity-content of theair;

' S urrounding the wet bulb element is the V oe'ramic ewick 22 of the-present invention "whijchimay belconsideredfas being a part of the wet bulb element, VAsshown in Fig ur'e'Q it-is formed in one integral body hav} ingacyli'ndric'alj shellgiwith a fin 22f pro; jecting downward therefrom: Thisfin, dipsf f v under v iater in a suitably long and narrow, Welhor' re'servoir 2%, from which vvater'is" V drawn up through the ores-of the 'material by ='oapillary action into the part offthe shell immediatelysurrounding the ii'vet bulb element-Q Preferably thei'spacei inside the shell I is vslightly. larger 'than'lthe element. 20 in 7 order that the latter may be substantially free from; contact therewith, From; this shell the water evaporates, freducingfthe temperature ofy thepwet bulb element more orJ-less, according to the rate of evaporation,

which, in turn'depends iiponthe degree of humidity in I the atmosphere. 'This I; prorace The freedom from'such held'particles prevents loss of'the desired state of super;

either visibly, asat the "thermOmeterBO, or I "operatively as in the case of the thermorepresents the coincidenttemperatureof at; p v mosphere, and these two ,co-operate in de- .termining the setting'of the ratio'valve'} 16.

The function ot the latter is, on proper occasions, to admit air-under =pressure to the diaphragm valve 14-, whereby the lever '12, isswung to shut off escape through the lever valve '10, This results' in" the initia tion of gaction by the humidifying apparatus to deliver moisture to-the atmosphere.

As the relative humidity of the air increases, the 'evaporationof'water from the temperature in the iwet bulb element, from relative elongation of this element; This inturn affects the setting of the ratio valve, until, when the moisture oontent of theiatmosphere has reached a. predetermined de gree, the ratio valve vvill'close,andthereby J humidifying apparatus;

will bring about a cessation of aetion I have determined by test that sible to have a'kind and grade of ceramic, 'materialin Whiohthere is an approximate Y balance between the amount:- of 'Waterj'f wick, and the: amount jot water ei'rapora'ted Wet. Ihave'furthe'r found that a Wick suitable for useat high humidity alsoproduces I substantially the hygrometric Wet bulb temperatures at low humidity. 3 From this it's followsthat in choosingtheproper grade of ceramic material, one need but: select a I r grade that Will give the desired resultsat' the maximum degree of humidity at which it is to be used, and thereafterfthe vvetbulb' member Will represent atmosphericconditions of humidity with the accuracy which is requisite for the practical and reliab e operation applied; a 7 s K l In consequence of its freedom from' sensible moisture, and the absence of "filament of the apparatus tov'vhich it i's T tary projections, particles floating'in the air are not caught'and held on the Wicks surficial dryness. Impurities found in Water under ordinary operating conditions do not appear to affect operation of the Capillary ce ramic passages vvhich lead this surface from the wellbeneath. 5

In Figure'S'the W16]; is illustrated as "it?" may be made in two parts, 22 and 22 r I each part forming approximately .one halfof the shell and each having. its extension f into "the welli "non-corrosive clips'26 may serve to hold the parts together about the 7 wet "element. .7

i In the controller illustrated there are the usual dry'and wet bulb thermometers 28,

SOQ Tlie l atter,iat the right, is provided with'aceramic wick- 32-shape'd to conform to the configuration of the bulb, and dipping into'the water inethefwell 24:;below. I j we Asjthedegree of coarseness of the ceramic material chosen increasesfajgreater e'vapo-f rative power is necessary to-kee'p its sur- .face dry. Hence it may be [found in pra c-- tice that where thecapillarypower is relatively largeithe surface maybec'oine wet at the higherdegrees of humidity. Neverthes less, thebenefits of the-invention may be had whenever the operative" range at which the apparatus is expected ordinarily'to work is low enough sothat the evaporative power equals or exceeds the capillarypower.

And even when the suriace becomes wet there Stlll remaln some Lv 'advantages from the use of the material described.-

'. Although the invention has been herein described as it may be applied in apparatus wherein the wick is in closekproximity to' the wet bulb element whichlis to be cooled thereby, it will be understood that the bene device :being of porous, capillary ceramlc' materialhaving a surface. free from filamen= tary projections. g "2. A capillary and evaporative cooling device, fora thermally responsive element, made of ceramicv materlal having capillary capacity in such relation to its capacity for evaporation that theexposed tangible surface of said device is not sensibly Wet by the I devlce vfor a thermally responsive element,

capillary feed. H v e A wi kof, ceramic material arranged for supplying moisturetobe evaporated in the region of a thermallyresp'onsive element; said wick having a relatively smooth surface and having pores so-fine that the exposed tangible surfacelis maintained not wet.

4. A 'wiok of rigid, earthy material for supplying moisturejto be "evaporated in the region of a thermally responsive element,

having such a relation between its capillary and its evaporative powers that only as much water is, supplied as is immediately 7 evaporated, thereby leaving the surface of the wick substantiallydry; a

5, The combination of a' capillaryand the elementciscooled.

which a part is immersed in liquid, and an- A evaporative cooling device with a thermally' T c c respons ve element; a mechanism arranged H p other part is exposed on all sides to my said stiff body having a spa ce'vvithin it in which said element is set'substantially free from contact therewith.

7 A capillary and evaporative cooling device for a thermally responsive element, comprising the combination,withsaid element,

of a liquid supply; a receptacle for the element, having walls of stiff, porous material capable o flosing moisture by evaporation, constituting a chamber, for receiving the element, of such dimension as provides anevaporative space between said element and said walls; and means for supplying liquid, to said chamber walls; the whole ing a wet bulb elementlf 8. A capillary and evaporative cooling deconstitutvice for a thermally responsive element, compr sing a receptacle, made" of ceramic jmate'rial within which said element may be! placed and remain dry; the walls of said receptacle being capable of losing moisture by 1601 evaporation, and capillary feeding means for supplying moisture thereto.

9. A capillary and 'evaporative cooling de viceiorathermally responsive element, comp e 10,53 exterior and interior tangible surfaces of prising areceptacle with ceramic walls the V which are dry, and capillary feeding means 7 for supplying moisture to the internal portions of said walls; thesaid walls beingcapable of losing said moisture by evaporation without the said 10.A capillary and" evaporative cooling comprising a receptacle of ceramic material wltha portlon immersed in and a portion upstanding from'a supply of liquid,;said upv standing portion ha'vingfa dry chamber for recelving sa d element;- the saidupstandmgportion taking moisture from sai'd immersed,

portion by capillary feed and being capable of losing the same'by evaporation whereby Rhbde island, this Signed at Providence,

twenty-sizrth day of January, 1924c.v

V r ALBERTJ. OE N E 110 surface becoming sensibly 

